ArcGIS Desktop – Finding Nearest Line to Point

arcgis-10.0arcgis-desktoparcobjectsarcpyproximity

I am new to building custom ArcObjects, and am looking for a custom python script for arcgis version 10 that will loop through a point shapefile to find the nearest line segment of a line shapefile (or multiple if possible) and add the 'NAME' attribute from the line shapefile to a new 'STREET' attribute in the point shapefile.

Best Answer

You should use the Near command. It will create a Near_FID field which is the FID of the nearest Line Feature. Just join on this and you should be able to Calc your points with the closest Line Name. Should be a short script.

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[GIS] Finding Nearest Feature Methods VB ArcObjects

OK so my co-worker helped me figure this out...

Turns out I hadn't declared an envelope for my featureIndex, which in turn, left my indexQuery empty.

Underneath:

    Dim pNhdIndexQuery As IIndexQuery2

I added the following lines of code:

    Dim pEnvelope As IEnvelope
    Set pEnvelope = New Envelope
    pNhdFeatureIndex.Index Nothing, pEnvelope

This comes before:

    Set pNhdIndexQuery = pNhdFeatureIndex

You also need to ensure that the projections of your data frame, sourceindex, and inpoints all match, lest you catch an error.

Hope this helps,

ArcPy – Finding Mid-Point of Line in ArcGIS 10.0

The Polyline class has a new method called "positionAlongLine" in ArcGIS 10.1. This will return a PointGeometry object with exactly one point at a specified distance from the starting end of the line, or a fraction of the distance between the start and end. To find the midpoint, you would just need to do positionAlongLine(0.5,True). To find the midpoints for lines and add their coordinates to the attribute table, you could do Field Calculator on the following statement:

!Shape!.positionAlongLine(0.5,True).firstPoint.X
!Shape!.positionAlongLine(0.5,True).firstPoint.Y

Note that you need to be using the Python parser in field calculator for this to work.

If you wanted to access this point object in Python, you would just do the following:

Input_shp = "C:\Temp\Line.shp"
Cursor = arcpy.SearchCursor(Input_shp)
for Feature in Cursor:
    Midpoint = Feature.shape.positionAlongLine(0.50,True).firstPoint
    print Midpoint.X
    print Midpoint.Y

Best Answer

Related Solutions

[GIS] Finding Nearest Feature Methods VB ArcObjects

ArcPy – Finding Mid-Point of Line in ArcGIS 10.0

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